ASTM D4991 Leakage Testing of Containers by Vacuum Method
ASTM D4991 covers the testing of empty containers for resistance under differential pressure conditions. As an ISTA and ISO 17025 certified lab, we realize the importance of leakage testing of empty rigid containers. Meeting the ASTM D4991 requirements can be difficult. We understand the challenges and guide companies through the process.
Keystone administers accurate test reports that are delivered quickly. Our pricing is competitive and we offer volume discounts. We also provide the peace of mind that all of your needs will be met. Therefore, our proven process helps avoid product launch delays.
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Summary of ASTM D4991 Leak Testing Information
As mentioned above, the ASTM D4991 test method covers the testing of empty containers under differential pressure conditions. Examples include those which can occur during air transport. The ASTM vacuum method is suitable for testing rigid containers intended for the transportation of hazardous liquids.
This standard does not purport to address all of the safety concerns associated with its use. It is required to have suitable means to hold the test specimen with a closure not more than 25mm under the surface of the test fluid.
Scope of the ASTM D4991 Vacuum Method
An empty rigid container is pressurized by immersion in an ethylene glycol-water solution and a transparent test chamber. The container is then subjected to a gradually increasing partial vacuum. Lastly, the container is observed for signs of leakage. Evidence is present when air bubbles during de-pressurization or fluid in the container after re-pressurization is found.
Prior to testing, a vacuum is drawn to at least a 95 kPA differential and maintained for 10 minutes in order to remove air dissolved in the fluid. More than one specimen can be tested at one time provided that there is sufficient space in the testing chamber. This allows clear observation of each specimen.
Significance of Rigid Packaging and Leak Testing
Containers may be pressurized in accordance with this test method without modification to the closure or the body of the container. This test procedure established the point at which leakage starts, with a limit of 95-kPa differential. See test method D3078 for flexible packages.
ASTM D4991 is not suitable for some packages. This includes packages with paper cap seals. Furthermore, leakage testing is not fitting for packages where the test fluid may rapidly deteriorate the packaging.
Test specimens consist of containers including their closures. The containers are emptied and cleaned prior to the testing. Lastly, each container is closed for testing in the same manner as it would be closed for actual shipment. Unless otherwise specified, use at least three test specimens.
The test report includes the following information:
- Total number of specimens tested
- Number of specimens tested at one time
- Test pressure requirement
- Whether each test specimen leaked and at what pressure differential
- Whether the test was performed at ambient temperature
- Whether the test fluid was apparent in each test specimen after testing
Expert ASTM D4991 Rigid Container Package Testing
Keystone has a full lab of test equipment which permits us to provide short lead times on scheduling. In addition to ASTM D4991 performance testing, Keystone has a full scope of expertise including cold chain, temperature validation, and sterile barrier. We can accommodate flexible and rigid packages of all sizes, including large pallets.
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